In this work, we proposed new sample preparation technique (combination of mechanical and chemical method) for inspection of intermetallic bondballs. The use of this new method will provide more accurate estimation of the percentage of intermetallic formation area. The procedure to perform the sample preparation is: 1. Grind unit from the bottom side of the package until the bulk silicon die is visible. 2. Dipping the unit into KOH 50% solution at 100 to 110 degree C to remove the bulk silicon 3. Dip unit in HF : DI water (1:10) at room temperature to remove any diffusion layers, metal lines, barrier metal and inter-dielectric layers. Then clean the unit by using Hydrogen Peroxide (H2O2) 4. The images are imported into Image-Pro software to calculate the percentage values.